Stencilled on a shutter at the entrance to London Zoo, the mural showed a powerful gorilla lifting up the metal barrier and creating a dark hole just big enough for other animals to use to make a speedy getaway. Now, Banksy’s ninth and final artwork in his animal-themed London series has itself escaped, removed in an attempt by the 196-year-old zoo to “properly preserve” a “significant moment” in its history. The zoo previously warned visitors on social media that it was planning to remove the artwork from public display on Friday evening “for its safekeeping and to make full use of our entrance during the busy summer period”, informing people: “We’re still working on exactly what we’re going to do with [it].” It has replaced the work with a replica and a nearby sign that reads “Banksy woz ere” in the hope of preventing crowding at its entrance by fans of the anonymous artist, who have been appearing in droves after the work was unveiled on Tuesday. The shutter to the entrance had remained closed since then so that visitors could admire Banksy’s work, which portrayed a watchful gorilla helping a sea lion, several birds and bats and three other mysterious animals – depicted only by their three sets of glowing eyes – to escape into Camden. In a blog posted on Thursday, Kathryn England, the chief operating officer of the zoo, publicly thanked Banksy for stencilling his art on the zoo’s shutter, describing it as “a significant moment in our history that we’re keen to properly preserve”. She added: “We’re thrilled by the joy this artwork has already brought to so many, but primarily, we’re incredibly grateful to Banksy, for putting wildlife in the spotlight.” Until Friday evening, zoo officials had used a Perspex cover to “protect it from the glare of the sun”. Two other pieces in the series, which have appeared across London since 5 August, have been defaced, including the silhouettes of elephants in Edith Grove in Chelsea. The Metropolitan police were called to reports of a theft after the fourth piece, depicting a howling wolf on a satellite dish, was taken down just hours after it appeared. The sixth piece, featuring a stretching cat on a billboard, was dismantled by three men who said they were hired to take it down for safety reasons. The billboard’s owner later said the work would be reassembled at an art gallery. Last week, a spokesperson for Banksy told the Observer that the artist hoped the uplifting nature of the works would cheer people “with a moment of unexpected amusement, as well as to gently underline the human capacity for creative play, rather than for destruction and negativity”.